Annular capacity between casing and multiple tubing strings

Input(s)

$\mathrm{D}_{\mathrm{h}}$: Hole Size (in.)

$\mathrm{T}_{\mathrm{a}}$: Outer Diameter of Tubing No. 1 (in.)

$\mathrm{T}_{\mathrm{b}}$: Outer Diameter of Tubing No. 2 (in.)

Output(s)

AC: Annular Capacity (gal/ft)

Formula(s)

$$ A C=\frac{D_{h}^{2}-\left(T_{a}^{2}+T_{b}^{2}\right)}{1029.4} $$

Reference(s)

Lapeyrouse, N. J., 2002, Formulas and Calculations for Drilling, Production and Workover, Second Edition, Gulf Professional Publishing, Page: 14.